This invention relates generally to connectors for terminating fiber optic bundles such as glass fibers and more particularly the invention relates to a simplified fiber bundle terminating means comprising a single plastic element and a single metal ferrule.
There are several types of fiber bundle connectors presently available on the market. Those connectors which connect together two fiber bundles or two coaxial cables in a butt splice arrangement frequently consist of four sections, including a termination on the end of each of the fiber bundles to be connected together and a coupling means consisting of two sections which are joined together by suitable means such as a spring loaded bayonet type connection, with the terminations on the ends of the bundles being matable with open ends of the two coupling sections by threaded means for example.
One prior art means of terminating the fiber optic bundles consist of a generally cylindrically-shaped metal element having an aperture extending through the axis thereof which receives the fiber optic bundle. The aperture is divided into sections having diminishing diameters all concentric with each other and with the sheathed fiber optic bundle entering the largest diameter aperture section from a first end of the termination means and with the unsheathed fiber optic bundle extending through the terminating means and entering the smallest diameter portion thereof which opens onto the second end of said termination means, which second end first enters into one of the two coupling sections. The second end of said metal termination means is usually tubular in shape and crimped directly around the glass fiber bundle. The end of the tubular section is ground so that the glass fibers retained therein terminate in a plane perpendicular to the axis of the aperture and have a desired predetermined length measured from a reference point, such as a shoulder formed on the metal termination means, to thereby ensure that the ends of one optic bundle will abut against and mate with the ground end of a second optic bundle within the coupling means.
A metal termination means further requires a spring loaded nut secured therearound which is abutted on one side against a shoulder on the terminating means and retained on the other by a "C" snap washer which fits within a groove formed around the circumference of the cylindrically-shaped termination means. Thus, the prior art structure for terminating a fiber optic bundle consists of four elements including a main, generally cylindrically-shaped body with a groove formed thereon and a smaller diameter tubular element at one end thereof, a metal nut positioned around the cylindrical-shaped body and backed up against a shoulder on one side thereof, a spring mounted within a cavity formed in said nut and a "C" snap washer snapped into a groove around said cylindrical body to spring load the nut on said cylindrical body.
It is to be noted that the above described prior art terminating means involves the crimping of the inside metal surface of a tubular element directly upon the glass fibers, which frequently results in damage to those glass fibers which are immediately adjacent the inside metal surface of the tubular element.
Further, the cost of such prior art means of terminating fiber optic bundles is quite high inasmuch as it requires four parts, all of which are metal and at least two of which must be machined, including the nut and the main cylindrical-shaped body.